SCIENCE CARRIES ON

Waipa Post, Volume 45, Issue 3202, 12 July 1932, Page 6

SCIENCE CARRIES ON

LONG-DISTANCE PHOTOGRAPHY

While the nation's leaders are busily engaged arguing world economics, science continues its progress unperturbed. One of the latest marvels is brought before the public mind by the London Times, which publishes a photograph of the shores of France taken from Dover.

It is now no longer necessary for a photographer to wait upon the weather when he wishes to photograph distant objects or scenery which the thickness of the atmosphere prevents him from seeing. His camera has acquired the power of penetrating mist and haze, or, rather, disregarding them as though they were not, and of recording objects within its range as clearly as if the image were presented through the most translucent atmosphere. The secret of this new photograph can be succinctly explained. One of the reasons why it is impossible to see far in misty or hazy weather is bebecause the moisture in the air scatters the light; but the light is scattered also on a fine day, though less when the light is yellowish or reddish, as toward sunrise or sunset. Red light indeed is scattered less than blue. The problem, therefore, has been how to use the infra-red. This is achieved by a so-called filter, or suitably dyed piece of gelatine, placed in front of the lens. It allows infra-red rays alone to penetrate and to carry the image; and;, though infra-red light is invisible to the eye, the sensitive material employed in the camera is responsive to it. The French coast, it must be added, has been brought all the nearer by a magnifying lens; but on the day of the photograph the unaided eye could barely see it, and the direction for the camera was worked out by compass. The photographer was some 300 ft. above sea level.